Use this excerpt from an article about the effects of the Korean War to answer the question.
It was the Korean War that erroneously persuaded US leaders that only the direct application of military power could contain what they now perceived as a dire Soviet threat menacing the entire world. The main legacy of Korea was that the United States thereafter pursued a foreign policy of global intervention emphasizing a reliance on military means to maintain the status quo. Had it not been for the flawed assumptions that US leaders derived from the Korean War, the Cold War arguably would have ended much earlier and at far less cost in both human lives and material resources.
What does this excerpt argue about the long-term effect of the Korean War on U.S. foreign policy?
The United States was motivated to build up its nuclear program.
The United States ignored the dangers of Nationalist dictatorships.
The United States believed only military intervention could stop communism.
The United States began to intervene for humanitarian reasons.